Power file safety construction



1957 c. D, GRABER ETAL. 3,306,691

POWER FILE SAFETY CONSTRUCTION 4 Sheets-Sheet 1 Filed Aug. 20, 1965INVENTORS CARL D.GRABER. LEOJ.GROSSWI LLER,JR.. THOMAS H.KENNY andHERBERT C.OBERM|LLER ATTORNEYS c. D. GRABER ETAL 3,306,691

ATTORNEYS Feb. 28, 1967 POWER FILE SAFETY CONSTRUCTION Feb. 28, W67

D. GRABER ETAL 3,306,691

POWER FILE SAFETY CONSTRUCTION Filed Aug. 20, 1965 4 Sheets-Sheet aTRANSFORMER 72 7O FUSE rvvvx MAGNET 79 r 63 M 66 54-1 If 76 a1 8O 3UR|zoRl uR2 60 AUTO I 75 MANUAL LS4 2 77 78 3DR| ZURI 2 INVENTORScARuiGRABERLEo J. GROSSWlLLERJR. THOMAS H.KENNXundHERBERTQOBERMILLERATTORNEYS Feb. 28, 1967 c. D. GRABER ETAL. 3,306,691

POWER FILE SAFETY CONSTRUCTION 4 Sheets-Sheet 4 Filed Aug. 20, 1965INVENTORS CARL D.GRABER. LEO J.GROSSW|LLER.JR.. THOMAS H. KENNY,ondHERBERT C.OBERMILLER ATTORNEYS United States Patent 3,306,691 POWER FILESAFETY CGNSTRUCTION Carl D. Graher, Orrville, Leo J. Grosswiller, Jr.,East Canton, Thomas H. Kenny, Navarre, and Herbert C. Ohermiller,Canton, Ohio, assignors to Diehold, Incorporated, Canton, Ohio, acorporation of Qhio Filed Aug. 20, 1965, Ser. No. 481,259

Claims. (Cl. 312-423) The invention relates to mechanized elevator orpower filing appliances of a type in which a plurality of pans aremounted on an endless conveyer for movement in either direction in acontinuous orbit of travel and any selected pan is delivered by conveyerdrive'power means at a work station, and in which a drawer, which may belatched in closed or retracted position, is supported on each pan onsuspension mechanism which permits the drawer to be moved betweenretracted and extended positions at the work station; and moreparticularly the invention relates to safety mechanism at the workstation arranged cooperatively with and actuated by the individualdrawer latch mechanism on any pan to prevent operation of the conveyerdrive power means when any drawer is unlatched or out of retractedposition in the region of the work station.

Safety devices for preventing operation of a power file when a drawerthereof is extended into the access open ing at a work station have beenprovided in mechanized power files such as in Patent No. 3,166,366.However, the operation of such prior safety devices depends uponproviding each of the many pans supporting drawers on the conveyer witha separate switch, associated with thedrawer latch and connected througha trolley device with the conveyor motor circuit to render the motorinoperative when any drawer latch is released or any drawer is moved outof retracted position.

This separate latch switch in such prior constructions on each panassociated with each file drawer is a normally-open switch when thedrawer is closed and latched in closed position. Any such switch closesa circuit to actuate a relay which cuts off power to the conveyer drivemotor when any drawer is unlatched.

Such prior power file safety devices thus comprise a substantial costfactor in the cost of the file because of requiring a large number ofrelatively expensive latch switches, one for each pan and because of thepotentially high maintenance cost since any one of the multitude oflatch switches may be subject to failure at any time. Another factor inthe potentially high maintenance costs involves maintaining carefuladjustments of the latch switch with respect to the pan, movable drawer,and latch mechanism for each drawer and switch to assure properfunctioning of the safety device.

Finally, proper operation of the safety device requires supplying powerto a circuit completed through the mechanism and wiring carried by eachpan. This arrangement does not provide fail-safe control since a brokenwire in any pan circuit or a failure of any switch on any pan willprevent operation of the safety device in instances where such operationis called for, until the circuit or switch is repaired.

Accordingly, objects of the present invention are to provide safetymechanism for a power file of the type described which is completelyfail-safe in operation; which requires only one switch rather than alarge number of switches for safety operation, thus drastically reducinginitial and maintenance costs for the safety system; which eliminatesspecial electrical circuitry and the necessity of supplying electricalpower to wiring and circuitry components carried by each pan-drawerassembly; which eliminates the necessity of frequent adjustment ofswitches and switch actuators on each pan-drawer assembly to maintainproper functioning of the safety system; which does 3,396,691 PatentedFeb. 28, 19 67 not require frequent critical adjustment to be made onthe single switch and actuating mechanism for the safety system; whichproperly functions as a safety mechanism even if there is power failure,a broken wire or a faulty switch in the safety system; and whicheliminates difficulties heretofore encountered in the art, achieves thestated objects in a simple, effective and inexpensive manner, and solvesproblems and satisfies needs existing in the art.

These and other objects and advantages apparent to those skilled in theart from the following description and claims, may be obtained, thestated results achieved, and the described difliculties overcome by theapparatus, combinations, parts, elements, subcombinations, arrangementsand constructions which comprise the present invention, the nature ofwhich is set forth in the following general statement, a preferredembodiment of which illustrative of the best mode in which applicantshave con-, templated applying the principlesis set forth in thefollowing description and shown in the drawings, and which areparticularly and distinctly pointed out and set forth in the appendedclaims forming part hereof.

The nature of the improved safety construction for elevator or powerfiles of the type in which a plurality of pans are mounted on an endlessconveyer mechanism for movement in either direction in a continuousorbit of travel and any selected pan is delivered by conveyer drivepower means at a work station, and in which a drawer, which may belatched in a closed or retracted position, is supported on each pan onsuspension mechanism which permits the drawer to be moved betweenretracted and extended positions through an access opening at the workstation, may be stated in general terms as including drawer latchmechanism mounted on each pan-drawer assembly, safety actuator rod meansmounted on each pan-drawer assembly movable from retracted to extendedposition upon unlatching the latch mechanism for such pandrawerassembly; the safety rod means for each pandrawer assembly when inextended position being located in a zone at one end of the pan-drawerassemblies parallel with the path of travel of the file conveyermechanism; trip-bar means mounted for movement on the file betweennormal and actuated positions adjacent the work station access openingand extending parallel with the path transverse in said zone by saidsafety rod means during movement of the conveyer past said access open.-ing; said trip-bar means being spring-biased to normal position and whenin normal position being adapted to be engaged and moved to actuatedposition upon movement to extended position of the safety rod means ofany pan-drawer assembly when the latter is located at an accessibleposition at the work station; preferably magnetic means for bringing thetrip-bar means to rent at normal position upon spring-biased movementthereof from actuated position; a single normally closed safety switchmounted adjacent and adapted to be engaged and actuated to open positionby said trip-bar means whenever-the trip-bar means is moved from normalto actuated position; and electrical circuitry and components connectingsaid safety switch and the conveyer drive power means whereby when anydrawer located at an accessible position at the work station isunlatched or located out of retracted position opening of said switch bythe extended safety rod means and actuated trip-bar means preventsoperation of the conveyer drive power means.

By way of example, an embodiment of the improved power file safetyconstruction is shown in the accompanying drawings forming part hereofin which:

FIGURE 1 is a persepctive view of a power filing appliance equipped withthe improved safety construction;

FIG. 2 is an enlarged side elevation with parts broken away and invertical section at various locations looking from the right side ofFIG. 1 and showing several pans with movable drawers adjacent an accessopening at a work station;

FIG. 3 is a fragmentary plan sectional view with parts broken awaylooking in the direction of the arrows 3-3, FIG. 2, showing a drawer ofa pan-drawer assembly in retracted and latched position;

FIG. 4 is an enlarged view of a portion of FIG. 3 illustrating thedrawer unlatched and being moved through the file access opening towardextended position;

FIG. 5 is an enlarged fragmentary front elevation with parts broken awaylooking in the direction of the arrows 5-5, FIG. 2, omitting the closurefor the access opening and illustrating several drawers accessible atthe work station;

FIG. 6 is an enlarged fragmentary top plan view of the safetyconstruction showing the trip-bar means in normal position;

FIG. 7 is a view similar to FIG. 6 showing the tripbar means in actuatedposition;

FIG. 8 is a fragmentary front elevational view of certain of the partsshown in FIG. 6 with the trip-bar in normal position;

FIG. 9 is a side elevation of certain of the parts in FIG. 8 lookingtoward the left of FIG. 8;

FIG. 10 is a sectional view looking in the direction of the arrows1tl10, FIG. 8;

FIG. 11 is a section taken on the line 11-11, FIG. 8;

FIG. 12 is a section taken on the line 12-12, FIG. 8; and

FIG. 13 is a wiring diagram for the safety construction.

Similar numerals refer to similar parts throughout the various figuresof the drawings.

The improved power file safety construction is illustrated and describedin the drawings in connection with a power file of the general typeshown in the K-rug et al. Patent No. 3,166,366. However, it is to beunderstood that the'improved safety construction may be incorporated inother power or elevator files such as shown in Patents Nos. 2,940,810,3,186,783, 3,198,894, or 3,199,658 or in power files equipped withdrawer ejector-retractor mechanism as shown in the copending Krug et al.application Serial No. 446,682.

A power file is indicated generally at 1 and may include a housing orcabinet 2, the front wall of which may be provided with an opening 3above a counter or Work station 4. A pair of conveyor chains 5 trainedover sprockets 6 and 7 mounted on upright support members 8 carried at 9within housing 2 mount a series of pans 16' for movement in eitherdirection in a continuous orbit of travel.

Each pan 10 is mounted at each end on a pair of arms 11 fixed to a chain5 and the arms 11 pivotally support an end of a pan 10 at .12. Astabilizing arm 13 is fixed to each end of each pan 10 having a roller14 at its other end. Rollers 14 engage and are guided in movement aroundthe upper and lower ends of the path of conveyer travel by semicircularguide channels 15 and 16 to maintain the pans 10 in a horizontalposition throughout the upper and lower ends of the orbit of travel onconveyer 5 when traveling around the sprockets 6 and 7. Horizontolpositioning of the pans 10 is maintained during travel in the verticalflights between sprockets 6 and 7 by engagement of a V-ear .17 at eachend of one pan with the pivot shafts 12 of the pan next below.

Conveyor 5 is driven in a suitable manner from drive means 18 which mayinclude a reversing motor, operated preferably by selector switches anda rotary selector control switch, not shown, of a type such as disclosedin Patent No. 3,198,894. The construction and operation of the conveyer,housing, etc. also briefly described herein may be of the type shown inPatent No. 3,199,658.

Power files such as shown in Patent Nos. 3,166,366, 3,198,894 and3,199,658, comprise a plurality of pans mounted on an endless conveyerfor movement in either direction in a continuous orbit of travel. Anyselected pan is delivered by power operation of the conveyer oppositethe work station 4. When delivered opposite such work station, a draweron a suspension mechanism on its pan can be moved manually between aretracted and an extended position such as shown in dot-dash lines at 19in FIG. 2, and likewise can be moved manually from extended position 19to a retracted position located in the path of the orbit of travel, suchas shown in the full line position of pans 10 in FIG. 2. Alternatively,such drawers may be moved between extended and retracted positions bypower mechanism such as shown in said application Serial No. 446,682.

Whether the drawers are moved between extended and retracted positionsmanually or by power operated mechanism, it is vital, to prevent damageto the file, that a safety mechanism be incorporated in the fileconstruction to prevent operation of conveyer 5 and motor 18 wheneverany drawer in any pan 1%) is not lached in retracted position.

In accordance with the invention, such safety operation of power file 1is accomplished by the improved safety construction best shown in detailin FIGS. 3 to 12 wherein the safety mechanism is generally indicated at20.

Each file pan 10 mounted on the conveyer has a drawer 21 mounted by ausual suspension generally indicated at 22 on the pan 10 so that drawer21 may be moved to an extended position as indicated at 19 in FIG. 2,FIG. 4 also showing a drawer 21 partially moved from retracted towardextended position. Drawer movement may be acomplished by grasping (FIGS.3, 4 and 5) the downturned handle flange 23 of movable drawer handle 24which is normally spring-pressed rearwardly of the drawer and pan by aspring 25 as shown in FIG. 3. A latch release actuator lug 26 projectsto one side of slide handle 24 near the front of the handle in positionto engage a lever 27 pivotally mounted at 28 on the base of pan 10 (FIG.4). Lever 27 is formed with a downwardly projecting pin 28a adjacent itsfree end which is engaged in slot 29 formed in interlock slide 30slidably mounted in a channel 31 in the base of pan 10. Interlock slide30 is fixed to one end of a latch and safety actuator rod 32 which isnormally spring-pressed by spring 33 toward the left of the pan 10 anddrawer 21. Rod 32 also preferably carries a stop collar 34 slidable inchannel 31 near the right-hand end of pan 10. A stop lug 35 is formed oninterlock member 30 projecting upwardly therefrom as shown in FIG. 4.

When slide handle 24 is in the position of FIG. 3 and drawer 21 isclosed, rod 32 is spring-pressed toward the left and stop 3-5 is infront of an elongated lock bar 36 mounted on the undersurface of drawer21. Also, stop collar 34 is in front of a downturned stop car 37 mountedon the undersurface of drawer 21 (FIG. 3). Thus, stop members 35 and 34,when engaging members 36 and 37, respectively, latch the drawer andprevent drawer 21 from being moved outward until such time as rod 32 ismoved to the position of FIG. 4 from the position of FIG. 3 in order toremove stop members 35 and 34 from in front of stop bar 36 and stop lug37.

Movement of rod 32 to the right is accomplished by moving slide handle24 forwardly of drawer 21 against the pressure of spring '25 from theposition of FIG. 3 to that of FIG. 4. Lug 26 engages lever 27 and swingsthe same so that pin 28a in slot 29 of interlock member 30 moves rod 32to the right. When this movement of the interlock mechanism has takenplace, the drawer 21 may be moved outwardly of its carrying pan 10supported on suspension mechanism 22. After drawer 21 moves forwardly onpan 10 from the in position of FIG. 3 toward an extended or out positionas illustrated in FIG. 4, stop bar 36 engages stop lug 35 on interlockmember 30 to hold rod 32 projected toward the right.

Thus, any drawer 21 may be released from latched position when in, byforward movement of slide handle 24, either by manually grasping thehandle flange 23 to pull the handle forwardly or.by pushing the rear ofthe handle 24 when the drawer is ejected by pow-er means. During initialmovement of slide handle 24 as described, the drawer first is unlatched.Then drawer movement from in to out position is accomplished. Afternnlatching, control rod 32 is interlocked and held in the projectedposition shown in FIG. 4 by stop bar 36 until the drawer is returnedagain to in position and latched in such position.

The improved safety mechanism 20 is actuated by the actuator head 38 onactuator bar 3-2 carried by pan and head 38 projects beyond theright-hand end of pan 10 as shown in FIGS. 3 and 4. Safety mechanism 20includes a channel base member 39 having a web portion 40, a long leg 41and a short leg 42. Leg 41 of member 39 is bolted at its upper end bybolts 43 to an upper pad mounting member 44 bolted at 4-5 (FIG. 5) tofile support member 8; and the lower end of leg 41 of member 39 -isbolted at 46 to a lower pad mounting member 47 (FIGS. 3 and 4) alsobolted at 48 to support member 8. A trip-bar member 49 is pivotallymounted at 50 and 51 on member 39 and is spring-biased to normalposition '(FIG. 6) by spring 52 extending between a clip 53 mounted ontrip-bar 49 and an angle clip 54 mounted on the leg 41 of member 39(FIG. 11). Member 49 when moved to normal position of FIG. 6 by spring52, engages cushion pads 55 and 56 between the flange 57 of member 49and web 40 of member 39. An angle bracket 58 is mounted on flange 57 ofmember 49 adapted to engage roller 59 of safety switch 60 when in normalposition of FIG. 6 and adapted to release switch roller 59 when member49 is moved to the angled or actuated position of FIG. 7. Switch 60 ismounted on an angle bracket 61 carried by web 40 of member 39.

Another angle clip 62 preferably projects from flange 57 of member 49below spring mounting clip 53 (FIG. 8). Clip 6-2 is in position to beattracted and engaged by electromagnet 63 mounted on bracket means 64(FIG. 10) carried by web member 40 and projecting through an aperture 65formed in web member 40. A rectifier 66 also is preferably mounted at 67on bracket means 64 immediately adjacent electromagnet 63 for supplyingdire-ct currentto energize the electromagnet 63 when desired.

Trip-bar 49 has a generally vertically extending shoe portion 68 locatedas shown in FIGS. 3, 4 and 5, in a position to be engaged by anyactuator head 38 on any actuator bar on any pan 10. Shoe portion 68preferably terminates at its upper and lower ends in angular por- Itions 69.

. Referring to FIGS. 3, 4 and 5, the actuator head 33 of any actuatorbaror rod 32 when in extended position is located in a zone at one endof the pan-drawer assemblies parallel with the path of travel of theconveyer mechanism. Furthermore, the elongated trip-bar shoe 6 8 alsoextends parallel with the path traversed in said zone by said safety rodmeans during movement of the conveyer past the access opening 3. Also,the trip-bar member 49 is mounted onits pivots 50 and 51 for movementbetween the normal position of FIG. 6 and the actuated position of FIG.7. When in normal position, the trip-bar shoe 6-8 is adapted to beengaged and moved to actuated position upon movement to extendedposition of the actuator head 38 of any safety rod member 32 of anypan-drawer assembly when any such pan-drawer assembly is located at anaccessible position at the work station.

. That is, referring to FIG. 5, the trip-bar shoe 68 extends beyond theupper and lower boundaries of access opening 3 of the file. Thus, whenany drawer handle 23-24 of any drawer accessible at opening 3 can bereached and manipulated to unlatch the drawer, the actuator head 38 oflatch bar 32 of such drawer will engage safety shoe 68 and move it toactuated position of FIG. 7 when the drawer is unlatched.

The electromagnet 63 operates to bring the trip-bar 49 to rest at normalposition whenever the trip-bar is moved by spring 52 from actuatedposition of FIG. 7 to normal position of FIG. 6. Normally theelectromagnet 63 is deenergized when trip-bar 49 is in normal position.How ever, whenever trip-bar 49 is moved to actuated position, circuitryand electrical components connected with electromagnet 63 complete acircuit thereto and energize the magnet. Then, whenever the actuatorhead 38 which is holding the trip-bar 49 in actuated position of FIG. 7,is released by closing of a drawer whose actuator head 38 is projected,spring 52 will suddenly and quickly move the trip-bar 49 back to normalposition of FIG. 6. The suddenness of this movement and the strength ofspring 52 may cause trip-bar 49 to bounce or vibrate until it comes torest at normal position. The energized electromagnet 63 which attractsand holds clip 62 on trip-bar 49 whenever the trip-bar is moved tonormal position prevents such trip-bar vibration. Upon reaching normaltrip-bar position, power to electromagnet 63 is cut out so as todeenergize magnet 63 as soon as trip-bar shoe 68 has come to rest atnormal position. Usual electrical delay means may be introduced into thecircuitry for magnet 63 to momentarily delay deenergization of magnet 63for a short period of time after trip-bar 49 has come to rest at normalposition.

Safety switch 60 is electrically connected in control circuits to thedrive motor means and power means 18, and switch 60 is normally closed.Thus, when trip bar 49 is moved to actuated position of FIG. 7, car 58releases roller 59 of switch 60 permitting switch 60 to open therebyopening the circuit to the motor and power means 18, and stopping powerdrive for the conveyer mechanism. Thus, movement of the conveyer isprevented whenever any drawer is unlatched because such unlatchingprojects an actuator head 38 on the pan carrying the unlatched drawer toa position to move trip-bar 49 to the actuated position of FIG. 7.

These relationships provide fall-safe operation of the safety devicesince the effectiveness of the safety device is not dependent uponenergizing a circuit when the safety device is actuated. Rather, itseffectiveness depends upon opening the motor drive circuit by openingswitch 60. Accordingly, power failure, or failure of a wire or a switchin the circuit in which switch 60 is located also will prevent operationof the drive motor.

The operation of the improved construction with reference to the controlcircuitry may be understood with reference to the simplified wiringdiagram of FIG. 13. Whenever the conveyor is stopped and the accessopening 3 open at the work station 4, a drawer 21 on any panlt) may beunlatched-and pulled or ejected to an extended position. Uponnnlatching, the actuator head 38 on the actuator rod 32 for suchpan-drawer assembly is moved to the position of FIG. 7, moving trip-bar49 to release roller 59 of switch 60. Switch 60 is preferably a doublethrow switch having one blade or contact LS42 that is normally closedwhen the trip-bar 49 is in the position of FIG. 6, and the other bladeLS41 of which is normally open. Release of roller 59 of switch 60permits LS42 to open and LS41 to close as shown in FIG. 13.

Low voltage control circuit power is supplied. from transformer 70connected with power supply lines 71 and 72 to the control circuitthrough output lines 73 and 74. Line '73 may be connected through line75 with an alternate action automatic-manual switch 76. When switch 76is actuated to close manual contacts 77 and 78, it completes either oftwo circuits to start the conveyer drive motor for either up or downmovement of the conveyer. One circuit includes up relay URZ, aninterlock relay 2DR1v and holding contacts 3UR1 for the up relay.

7 The other circuit includes down relay DR2, an interlock relay ZURI andholding contacts 3DR1 for the down relay. Either of the two circuits iscompleted from contact 78 to blade LS42 of switch 60.

Thus, when blade 60 is opened by actuation of tripbar 49, neither relayUR2 or DR2 can be energized for actuation of the conveyer drive means13. When either UR2 or DRZ is energized, it completes a circuit in theusual manner to the selected winding of the drive motor to drive theconveyer in the up or down direction depending upon whether the up relayUR2 or down relay DR2 is energized. Interlock relays ZDRI and ZURl arenormally closed as shown. Whenever down relay DRZ is energized,interlock relay 2DR1 is energized to open, thus preventing up relay UR2from being energized. Similarly, ZURI opens when UR2 is energized toprevent DR2 from being energized. 3UR1 are holding contacts for the UR2relay which are closed when UR2 is energized and which open when thecircuit to UR2 is opened as by opening blade LSd-Z of switch 60.Similarly, SDRii are then holding contacts for down relay DR2.

Whenever LS42 has opened by actuation of trip-bar 49, LS4-1l closes.This switch blade LS4-1 is connected between power supply lines 73 and74 with rectifier 66 which, when energized, supplies direct currentthrough lines 79 and 8t) to electromagnet 63.

Thus, whenever the trip-bar 49 is in the position of FIG. 7, magnet 63is energized. When trip-bar 49 is suddenly released, spring 52 movestrip-bar 49 back to the position of FIG. 6 and the magnet attracts andholds trip-bar 49 in normal position against vibrating. When trip-bar 49reaches the normal position of FIG. 6, roller 59 of switch 60 is engagedactuating the switch to close contacts LS42 permitting the conveyermotor to be energized and interrupting power supply to the rectifier 66.Magnet 63, however, is subject to residual magnetism after beingenergized when power supply thereto is cut off. This residual magnetismis sufficient, for a short period of time, to hold the trip-bar 49 innormal position until its movement is brought to rest. Thereafter, theresidual magnetism dissipates permitting the trip-bar 49 again to bemoved to actuated position upon engagement by any actuator head 38.

The automatic-manual switch '76, if actuated to automatic position,completes a circuit to line 81. which may be connected to suitableselector button and rotary switch circuits, not shown, for automaticoperation of the file to deliver any pan to the work station uponpressing a selector button corresponding to the pan. These arrangementsare illustrated in Patents Nos. 3,198,- 894 and 3,166,366 and in saidapplication Serial No. 446,682.

As indicated, only one switch 6% is required to serve as a safety devicefor all pan-drawer assemblies in the file thus minimizing the cost ofand maintenance expense for the safety mechanism.

In addition, no adjustments that need to be made within close limitswith extreme care are required since the safety mechanism structureprovides for considerable movement (FIGS. 6 and 7) of both the actuatorhead 38 of the pan-drawer latch actuator rod 32 and also considerablemovement of the movable trip-bar 49.

Accordingly, the improved construction provides a simple and readilyoperated safety mechanism for power files of the character described;provides a construction that avoids the various difficulties andeliminates the problems involved in the construction and operation ofprior safety mechanisms; and provides a new construction achieving theobjects set forth and accomplishing the many new functions and resultsdescribed, thereby solving problems existing in the art.

In the foregoing description certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom beyond ;the requirements of the prior .art, becausesuch terms 8 are used for descriptive purposes and are 'intended to bebroadly construed.

Moreover, the description and illustration of the invention is by way ofexample and the scope of the invention is not limited to the exactstructures shown, because the various parts, components and mechanismsmay be varied to provide other structural embodimnets, without departingfrom the fundamental concepts, aspects and principles of the invention.

Having now described the features, discoveries, and principles of theinvention, the construction, assembly, characteristics, operation anduse of a preferred form thereof, and the advantageous, new and usefulresults obtained thereby; the new and useful discoveries, principles,apparatus, combinations, parts, elements, subcombinations, structuresand cooperative relationships, and mechanical equivalents obvious tothose skilled in the art are set forth in the appended claims.

We claim:

1. Safety construction for a power file of a type in which a pluralityof pans are mounted on an endless conveyer mechanism for movement ineither direction in a continuous orbit of travel and any selected pan isdelivered by conveyer drive power means at a work station, and in whicha drawer which may be latched in retracted position is supported on eachpan as a pan-drawer assembly on suspension mechanism which permits thedrawer to be moved between retracted and extended positions through afile access opening provided in the file case at the work station;including drawer latch mechanism mounted on each pan-drawer assembly;safety actuator rod means operatively connected with the latch mechanismmounted on each pan-drawer assembly movable from retracted to extendedposition upon unlatching the latch mechanism for such pan-drawerassembly; the safety rod means for each pan-drawer assembly when inextended position being located in a zone at one end of the pan-drawerassemblies parallel with the path of travel of the file conveyermechanism; trip-bar means mounted for movement on the file betweennormal and actuated positions adjacent the work station access openingand extending parallel with the path transversed in said zone by saidsafety rod means during movement of the conveyer past said accessopening; said trip-bar means being spring-biased to normal position andwhen in normal position being adapted to be engaged and moved toactuated position upon movement to extended position of the safety rodmeans of any pan-drawer assembly when the latter is located at anaccessible position at the work sta tion; a single safety switch meansmounted adjacent the trip-bar means and held in normally closed positionby said trip-bar means when the latter is in normal position; saidsafety switch means being released by said trip-bar means to openwhenever the trip-bar means is moved from normal to actuated position;and electrical control circuitry connecting said safety switch means andthe conveyer drive power means; whereby when any drawer located at anaccessible position at the work station is un latched, opening of saidswitch by the extended safety rod means and actuated trip-bar meansprevents operation of the conveyer drive power means.

2. The construction defined in claim 1 in which the trip-bar means ispivotally mounted within the file case adjacent the access opening atone side of the conveyer mechanism; in which the file case is formedwith upper and lower access opening boundaries; in which the tripbarmeans include a shoe extending parallel with the path transversed bysaid safety rod means during movement of the pan-drawer assemblies onthe conveyer mechanism past the access opening; and in which said shoeextends beyond said upper and lower access opening boundaries; wherebywhen any drawer accessible at the access opening is unlatched, thesafety rod means for such drawer engages the trip-bar shoe and moves thelatter to actuated position releasing the safety switch means to open.

3. The construction defined in claim 1 in which the tripbar meansincludes a base member mounted on the file, a trip-bar member pivotallymounted on the base member having a shoe extending parallel with thepath of travel of the conveyer mechanism past the access opening, andspring means tensioned between the base and trip-bar members holding thetrip-bar member springabiased in normal position adjacent but spacedfrom the path transversed by the safety rod means on the pan-drawerlassemblies; and in which the safety switch means is mounted on saidbase member and engaged by said trip-bar member to hold the switchnormally closed when the trip-bar member is in normal position.

4. The construction defined in claim 3 in which the tripbar member isprovided with a flange located adjacent the base member when thetrip-bar member is in normal position; and in which cushion means areengaged between the flange and base member to cushion spring-tensionedmovement of the flange toward the base member when the trip-bar memberis moved by the spring means from actuated to normal position.

5. The construction defined in claim 1 in which the tripbar meansincludes a base member mounted on the file, a trip-bar member pivotallymounted on the base member on a generally vertically extending taxisadjacent the access opening and having a shoe extending generallyvertically parallel with the path of travel of the conveyer mechanismpast the access opening; the shoe moving away from the conveyerpan-drawer assemblies located adjacent the access opening when thetrip-bar member pivots on the base member from normal to actuatedposition; and spring means tensioned between the base and trip-barmembers holding the trip-bar member spring-biased to normal positionadjacent but spaced from the path transversed by the safety rod means onthe pan-drawer assemblies.

6. The construction defined in claim 1 in which the trip-bar meansincludes a base member mounted on the file, a trip-bar member pivotallymounted on the base member having a shoe extending parallel with thepath of travel of the conveyer mechanism past the access opening; inwhich the safety switch means is mounted on the base member; and inwhich the trip-bar member is provided with a bracket engaging andholding the safety switch means normally closed when the trip-bar memberis spring-biased to normal position.

7. The construction defined in claim 1 including electromagnet meansmounted on the trip-bar means energized when the trip bar means is outof normal position to magnetically attract and bring the trip-bar meansto rest at normal position upon release of the trip-bar means forspring-biased movement from actuated to normal position.

St The construction defined in claim 7 in which the control circuitryincludes magnet switch means, and in which the magnet switch means isopen when the safety switch means is closed and the magnet switch meansis closed when the safety switch means is open.

9. The construction defined in claim 8 in which the electromagnet meansis energized by direct current when the magnet switch means is closed,and in which residual magnetism in the electromagnet means brings thetrip-bar means to rest at normal position by magnetic attraction afterthe magnet switch means has been opened upon spring-tensioned movementof the trip-bar means to normal position.

10. In a power file of a type in which a plurality of pans are mountedon an endless conveyer mechanism for movement in either direction in acontinuous orbit of travel and any selected pan is delivered by conveyerdrive power means at a work station. and in which a drawer which may belatched in retracted position is supported on each pan as a pan-drawerassembly on suspension mechanism which permits the drawer to be movedbetween retracted and extended positions through a file access openingprovided in the file case at the work station; the combination of asafety switch mounted within the file case; electric control circuitryconnecting the safety switch and the conveyer drive power means operableto permit operation of the conveyer drive power means when the switch isclosed and to prevent operation of the conveyer drive power means whenthe switch is open; trip-bar means pivotally mounted in the file caseadjacent the work station access opening having an elongated shoeextending parallel with the path of travel of said pan-drawer assembliesduring movement thereof past the access opening; said trip-bar meansshoe being movable between a normal position engaging and holding saidswitch closed, and an actuated position releasing said switch means toopen; spring means urging said trip-bar means to normal position; safetyrod actuator means mounted on each pandrawer assembly spring-biased fromretracted to extended position whenever the drawer of the assembly isunlatched; the safety rod means of any unlatched pandrawer assemblyaccessible at the access opening engaging the trip-bar means shoe andmoving the trip-bar means shoe to actuated position; and electro-magnetmeans mounted on the trip-bar means energized when the shoe is out ofnormal position to magnetically attract and bring the shoe to rest atnormal position upon release of the trip-bar means for spring-biasedmovement from actuated to normal position.

References Cited by the Examiner UNITED STATES PATENTS 3,166,366 1/1965Krug et a1 312-223 3,199,658 8/1965 Graber 198-137 3,236,577 2/1966Anders et 'al 312223 CLAUDE A. LE ROY, Primary Examiner. CHANCELLOR E.HARRIS Examiner,

1. SAFETY CONSTRUCTION FOR A POWER FILE OF A TYPE IN WHICH A PLURALITYOF PANS ARE MOUNTED ON AN ENDLESS CONVEYER MECHANISM FOR MOVEMENT INEITHER DIRECTION IN A CONTINUOUS ORBIT OF TRAVEL AND ANY SELECTED PAN ISDELIVERED BY CONVEYER DRIVE POWER MEANS AT A WORK STATION, AND IN WHICHA DRAWER WHICH MAY BE LATCHED IN RETRACTED POSITION IS SUPPORTED ON EACHPAN AS A PAN-DRAWER ASSEMBLY ON SUSPENSION MECHANISM WHICH PERMITS THEDRAWER TO BE MOVED BETWEEN RETRACTED AND EXTENDED POSITIONS THROUGH AFILE ACCESS OPENING PROVIDED IN THE FILE CASE AT THE WORK STATION;INCLUDING DRAWER LATCH MECHANISM MOUNTED ON EACH PAN-DRAWER ASSEMBLY;SAFETY ACTUATOR ROD MEANS OPERATIVELY CONNECTED WITH THE LATCH MECHANISMMOUNTED ON EACH PAN-DRAWER ASSEMBLY MOVABLE FROM RETRACTED TO EXTENDEDPOSITION UPON UNLATCHING THE LATCH MECHANISM FOR SUCH PAN-DRAWERASSEMBLY; THE SAFETY ROD MEANS FOR EACH PAN-DRAWER ASSEMBLY WHEN INEXTENDED POSITION BEING LOCATED IN A ZONE AT ONE END OF THE PAN-DRAWERASSEMBLIES PARALLEL WITH THE PATH OF TRAVEL OF THE FILE CONVEYERMECHANISM; TRIP-BAR MEANS MOUNTED FOR MOVEMENT ON THE FILE BETWEENNORMAL AND ACTUATED POSITIONS ADJACENT THE WORK STATION ACCESS OPENINGAND EXTENDING PARALLEL WITH THE PATH TRANSVERSED IN SAID ZONE BY SAIDSAFETY ROD MEANS DURING MOVEMENT OF THE CONVEYER PAST SAID ACCESSOPENING; SAID TRIP-BAR MEANS BEING SPRING-BIASED TO NORMAL POSITION ANDWHEN IN NORMAL POSITION BEING ADAPTED TO BE ENGAGED AND MOVED TOACTUATED POSITION UPON MOVEMENT TO EXTENDED POSITION OF THE SAFETY RODMEANS OF ANY PAN-DRAWER ASSEMBLY WHEN THE LATTER IS LOCATED AT ANACCESSIBLE POSITION AT THE WORK STATION; A SINGLE SAFETY SWITCH MEANSMOUNTED ADJACENT THE TRIP-BAR MEANS AND HELD IN NORMALLY CLOSED POSITIONBY SAID TRIP-BAR MEANS WHEN THE LATTER IS IN NORMAL POSITION; SAIDSAFETY SWITCH MEANS BEING RELEASED BY SAID TRIP-BAR MEANS TO OPENWHENEVER THE TRIP-BAR MEANS IS MOVED FROM NORMAL TO ACTUATED POSITION;AND ELECTRICAL CONTROL CIRCUITRY CONNECTING SAID SAFETY SWITCH MEANS ANDTHE CONVEYER DRIVE POWER MEANS; WHEREBY WHEN ANY DRAWER LOCATED AT ANACCESSIBLE POSITION AT THE WORK STATION IS UNLATCHED, OPENING OF SAIDSWITCH BY THE EXTENDED SAFETY ROD MEANS AND ACTUATED TRIP-BAR MEANSPREVENTS OPERATION OF THE CONVEYER DRIVE POWER MEANS.